Non-motor symptoms in Parkinson’s disease

Parkinson's disease (PD) includes motorial and non-motorial features, both negatively influencing patients’ life quality. While motor symptoms are well recognized and described, non motor symptoms are becoming a more recent focus of interest and research. This review aims to give an updated information about non-motor symptoms in PD. It comprehends three sections: 1) cognitive dysfunctions, 2) impulse control disorders and 3) emotional aspects. Articles from 2008 to 2013 were researched through the following keywords: non-motor symptoms in PD, cognitive disorders in PD, Parkinson's disease screening test, impulse control disorders in PD, neuropsychiatric disorders in PD, depression and apathy in PD, anxiety in PD. Cognitive impairments of PD subjects include the executive, attentional and visuospatial functions and are frequently associated with depression, anxiety and impulse control disorders (ICD). Hypersexuality, compulsive shopping, compulsive overeating, punding and pathological gambling are the most frequent ICD. PD is an insidious and multifaceted disease. Motor symptoms may only represent the tip of a massive iceberg where the hidden part consists of behavioural, cognitive and emotional symptoms. Some of these manifestations are intrinsic to PD while others are related to therapies. An early diagnosis of both motor and non-motor symptoms is hence desirable. The knowledge of these aspects may contribute to the development of novel treatment options in a multidimensional approach.